Purpose: To test check valve No. 2 for tightness against reverse flow.
Purpose: To test check valve No. 2 for tightness against reverse flow.
目的：检测止回阀2号对于回流的紧密度。
Purpose: To test check valve No. 2 for tightness against reverse flow.
目的：检测止回阀2号对于回流的紧密度。